In the early phases of requirements engineering, inspecting previously constructed conceptual models is important both for reusing specifications and for gaining general knowledge about how similar problems have been solved in other projects. However, as the users at this stage have only vague ideas about the system to be implemented, they are seldom able to specify a query to the CASE repository that is precise enough to capture the relevant conceptual models. In this paper, we present an information retrieval approach that frees the user from knowing the details of the modeling languages used in the repository and helps him retrieve models from other domains that are structurally similar to the one he intends to build. The system exploits the linguistic, semantic properties of the query to suggest what kind of representation he should look for, and it afterwards retrieves all models that are consistent with the query structure and the semantic representations of the words included in the query.